Signaling system and apparatus therefor



Nov. 13, 1934. s. MORTON ET AL 1,980,284

SIGNALING SYSTEM AND APPARATUS THEREFOR Original Filed July 11, 1930 4 Sheets-Sheet l FIG/1 7 INVENTORS STEEL/N6 MORTON HOW AED L. KEUM sownep E. KLEINSCHM/DT ATTO EY NOV. 13, 1934. 5 MORTON r AL 1,980,284

SIGNALING SYSTEM AND APPARATUS THEREFOR 'Original Filed July 11 1930 4 Sheets-Sheet 2 'IIfl/IIIIIIIIIIIIIIIIII INVENTORS: STEEL/N6 MORTON HOWARD L. KEUM sowneo E./1LEIN$CHMIDT BY ATT NEY Nov. 13, 1934. s. MORTON ET AL I 1,980,234

SIGNALING SYSTEM AND APPARATUS THEREFOR Original Filed July 11, 1950 4 Sheets-Sheet 3 INVENTORS STEEL/N6 MORTON HOWAED L. KEUM EDWARD E. KLEIN SCHMIDT Nov. 13, 1934. S..MORTON ET AL 1,980,284

SIGNALING SYSTEM AND APPARATUS THEREFOR Original Filed July 11, 1930 4 Sheets-Sheet 4 INVENTORS: STEEL/N6 MORTON OWA H ED 1.. KEUM saw/4120 E. KLEINSCHMIDT BY M I ATTOR Patented Nov. 13, 1934 SIGNALING SYSTEM AND APPARATUS THEREFOR Sterling Morton, Chicago, Howard L. Krum, Kenilworth, and Edward E. Kleinschmidt, Highland Park, 111., assignors to Teletype Corpora- 7 tion, Chicago, 111., a corporation of Delaware Original application July 11, 1930, Serial No. 467,352. Patent No. 1,904,164, dated April 18, 1933. Divided and this application May 31, 1932, Serial No. 614,364

32 Claims (01. 1782) The present invention pertains to signaling systems and apparatus therefor, and more particularly to selective signaling systems and apparatus for printing telegraph systems. i)

The present application is a division of application Serial No. 467,352, filed July 11, 1930, which eventuated into U. S. Patent No. 1,904,164, dated April 18, 1933, and relates particularly to improved means whereby a receiving operator, who in the act of receiving a message, may interrupt the transmitting operator and automatically condition the latters apparatus to receive messages.

This invention is especially applicable to communicating apparatus of the combination sending-receiving type, which is designed for interchanging messages between two or more points, and which consists of a keyboard transmitting unit and a printer or typing unit. In handling 29 telegraph communications it some times becomes necessary for the operator at the receivingstag tion to communicate with the operator at the sending station, and it is often very important that the receiving operator be able to interrupt the operation of the transmitting apparatus without cators transmitting apparatus inoperative and automatically condition said communicators receiving apparatus to receive messages.

Another object is to provide a send-receive break mechanism which is operable by means of code signals whereby the changeover is accomplished automatically through entirely mechanical means.

A better understanding of the invention may be had from the following description, taken with the accompanying drawings, wherein,

Fig. l is a front elevational view of a combination transmitting and printing apparatus embodying the present invention.

Fig. 2 is a left sideelevational view of the apparatus shown in Fig. l.

a clutch mechanism Fig. 3 is a fragmental plan view. of the apparatus shown in Fig. 1.

Fig. 4 is a view illustrating the relation between the selector mechanism and the function levers.

Fig. 5 is a schematic diagram of the electrical circuit at the sending and receiving stations.

Fig. 6 is a perspective view of the break mechanism.

Fig. '7 is a perspective view of the break mechanism with certain parts removed for clarity.

As set forth in the copending application of which this application is a division, the combination sending-receiving apparatus comprises essentially a printing unit and a keyboard transmitting unit. Although various forms of trans- 6 I with the keys are pivotally mounted on a common shaft 15 and are spring held in normal horizontal position .by individual springs 16. Arranged transversely below the key levers in operative relation thereto are a series of five notched selector bars 17 which are adapted tobe operated permutably in accordance with the key levers depressed.

The selector bars 17 are pivotally artic ated to a corresponding series of locking latclzes 18 (Fig. 1) which are adapted to be reciproca ed to either of two positions thereby. Associated with latches 18 are a corresponding series of contact levers 19 for making and breaking contacts 21. Contact levers 19 coact with individual contact cams 22 mounted on shaft 23. Referring to Fig. 3 it is noted that there is fixed on shaft 23 a gear 24 adapted to mesh with a gear 25 fixed to a main operating shaft 26 of the printer unit on which is affixed a main driving gear 27 which is adapted to mesh with pinion 28 of a driving motor (not shown). The shaft 23 is provided with (not shown), which is adapted to be controlled by a universal bar member as setforth in Patent No. 1,595,472. As fully sion of a key lever 14 which effects the arrangement of the set of selector bars 17 permutably in accordance with a predetermined code combination, the setting of which determines the position of the locking latches 18. The rotation of the cams 22 is initiated substantially simultaneously with the setting of the locking latches, and locking loop 29 controlled by cam 31 is permitted to rotate in a counterclockwise direction (Fig. 1) to efiect the locking of latches 18. Latches 18 are provided with pointed heads which when locked in place are disposed in one side or the other of the locking loop 29 in accordance with the setting of the selector bars 17. The setting of the locking latches 18 determines whether the contact levers 19 shall or shall not be affected by their associated cams 22 to eifect the opening or closing of their associated contacts 21 to transmit thereby over a line to the receiving station a predetermined code combination of signaling impulses. The respective notches in the cams 22 are arranged progressively such that upon the rotation of the cam assembly the contacts 21 will be controlled successively. The apparatus herein disclosed is operated in accordance with an equal length letter code, in which each code combination is a permutation of marking and spacing conditions and is preceded by a start impulse and fol-. lowed by a stop impulse, according to the familiar start-stop system.

These impulses are received by a single selector electro-magnet 33, Figs. 2 and 4, which operates a. selector armature lever 34. The electromagnet 33 is normally energized and becomes deenergized not only upon the receipt of a start impulse but also upon the receipt of spacing impulses of the code combination. The oscillations of lever 34 in correspondence with the energization and deenergization of the magnet 33 determine the position of a series of swords'35, as set forth in the copending application, which control the operation of a series of T-levers 36 to in turn set selector vanes 37 to correspond to the received code combination. Thus, as clearly set forth in said application, the setting of the selector vanes determines either the selection of a character to be printed or the selection of a function lever 38 (Fig. 4). A number of function levers are provided to perform the various functions, and when a function lever has been selected it is permitted to rotate slightly about a common pivot shaft 39 by means of its individual spring 41. In this manner the functions and operations of a remotely located printing appairatus may be selectively controlled. For further details regarding the printing operation, reference should be had to the copending application.

By the use of the send-receive break mechanism of this invention an automatic means is provided whereby the receiving operator may interrupt the sending operator either to have the sending operator repeat part of the transmitted message or, as some times occurs, the receiving operator may in turn desire to send to the sending operator or station a message of greater im-- portance or urgency, and so means has been provided whereby the receiving operator may inter-.

rupt the printer at the other end of the line and begin to transmit his own message.

This break mechanism, shown in Figs. 1, 3, 6 and 7, is located at the front of the apparatus and substantially to the left, to be the most conveniently situated for the use of the operator.

that the selecting unit may be lifted from the base unit without disturbing any of the adjustments between the two parts of the send-receive break mechanism. As indicated in Fig. 1, these two parts are divisible at 43.

That part of the break mechanism which is associated with the base unit 12 is shown in Fig. 6 and comprises a bracket 44 which is fixed to the base unit, and consists, primarily, of three electrical contacts 46, 47 and 48 (Figs. 1, 5 and 6) which may be operated either by hand through lever 49 from a position occupied by the operator of the printing apparatus, or by a lever 50 which in turn is controlled by a system of levers in the printing unit of the apparatus as shown in Fig.' '7.

Contact 46 is located in the signal line and is used as a break contact in the signal line circuit. For eikample, having reference to Fig. 5, it is observed that contact 46 is in the circuit extending from battery 51, wire 52, contact 53 of the transmitter contacts, wires 54 and 55, contact 46 (when closed), relay 58, wire 59, the distributor 61, line wire 62 to the receiving station, thence over a similar circuit at the latter station. Contact 47 is so wired as to shunt the sending contacts on the keyboard, thereby rendering the keyboard inoperative. From Fig.5 it is obvious that the contact 4'7 is in the circuit extending from battery 51, wire 52, contact 53, wire 54, contact 47, and wire 63 back to battery. Contact 48 is wired so that it may be placed in the control circuit of the transmitting distributor; for example, as seen in Fig. 5, contact 48 is in the circuit extending from positive battery through contact 48, wire 64, winding of start-stop relay 65 of the receiving distributor 61, tape controlled contact 66, manual switch 67, and wire 68 to negative battery. i

Lever 49, Fig. 6, by which that part of the break mechanism which is located on the baseunit 12 may be operated, can occupy any one of three positions. The intermediate position (which position is illustrated infull lines in Fig. 6) is called the receive position, the lowest position is known as the break position, and the uppermost position is the send position. When the lever 49 is in the send position, contact 46 in the line circuit is closed; contact 47, shunting the keyboard contacts, is open; and contact 48 in the transmitter distributor circuit is closed. When lever 49 is in the receive position, contact 46 in the line circuit is still closed; contact 47 shunting the keyboard contacts is also closed; and contact 48 in the transmitter distributor circuit is now open. In the extreme downward position of lever 49, known as the break position, contact 46 in the line circuit is opened, thereby cutting out the line circuit, and contacts 47 and 48 are closed and opened, respectively.

Besides being movable manually to each of the three aforementioned positions, lever 49 may also be moved automatically from the send to the receive position by means of a system of levers mechanically operated in the printing unit. It is, of course, manifest that lever 49 must be restored from the receive to the send position manually since placing the apparatus in the sending position is solely within the domain of the sender. Further, for a similar reason, lever 49 may be moved to the break position manually only,

by depressing lever 69 (Fig. 6) simultaneously mechanism is performed as follows: It will be as-" with lever 49. The depression of lever 69 releases a locking lever 71 from engagement with end 72 of lever 50, which simultaneous action with lever 49 will permit lever 50 to be moved from the "receive position to the break position to open contact 46, which will remain open so long as levers 49 and 69 are held depressed by the operator.

The send-receive break mechanism is shifted mechanically from the send position to the receive" position by means of the system of levers in the printing unit, as previously alluded to, when two or more successive blank code signals are received by the selector mechanism, as will now appear. Arms 73 and 74 of contact switches 47 and 48, respectively, are adapted to move together by reason of common insulator 75 secured thereto as clearly indicated in Figs. 1, 5 and 6. Pivotally connected at '76 to arm 77 of bracket 44 are levers 49 and 69. Lever 69 is substantially T-shaped, an arm 78 of which cooperates with arm 79 of locking lever '71 which is pivotally connected at 81 to an extension on bracket 44 and suitably positioned with relation to lever 50 to engage arm 72 thereof. At the end of the vertical arm of lever 71 is secured one end of a spring 82, the other end of which is secured to arm 83 of lever 69; the function of spring 82 being to hold lever 69 against stop 84, and simultaneouslyto hold lever '71 in engagement with arm 72 of lever 50.

As indicated in Figs. 6 and 7, lever 50 is pivotally connected at 85 to the rear wall of bracket 44, and is of substantially T-shaped construction comprising arms 72, 86 and 87. Arm 86 is provided with a laterally disposed portion 88 which co-acts with lever 89 on that part of the send-receive break mechanism associated with the printer unit 42, and vertical arm 87 is provided with a laterally disposed arm 91 which'actuates contact switch 46. Arm '72 of lever 50, is provided with a laterally disposed portion 92 to which is attached one end of a spring 93, the other end of which is fixed to bracket 44. Ann 72 is also provided with a two-position or double notch 94 to cooperate with arm 95 of lever 96 when lever 72 is moved to either its"send or "receive position. Appropriately positioned below lever 50 and pivotally connected at 9'7 to bracket 44 is three-armed lever 96, arm 95 of which has already been referred to. Arm 98 thereof is adapted to cooperate with lever 49, and arm 99 is provided 102, the other end of which is fixed to bracket' The manual operation of the send-receive break sumed that lever 49 has been rotated in a counterclockwise direction about pivot '76 (viewed in Fig. 6) to its uppermost or send" position, which position is substantially as shown by dotted lines, (Fig. 3). In this position the rear end of lever 49 is in engagement with end of arm .98 of lever 96 which lever has assumed the position, against the action of spring 102, such that arm 95 will.

rest in the deep portion of double notch 94 (Fig. 7). This position is attained by reason of the fact that the. downward movement of end 98 of lever 96 has imparted counterclockwise rotation to lever 96," thereby tripping arm 95 out of engagement with the shallow portion of notch 94, permitting lever 50 to rotate slightly in a counterclockwise direction under the influence of spring 93. The assumption of this position by lever 96 releases laterally disposed portion 101 thereof from engagement with contact switches 73 and 74, which assume their normal position such that contact 48 is closed and contact 47 is open. It will, therefore, be observed that this arthe message to the distant station; that is, the

contact 46 is closed. Secondly, the keyboard is connected electrically to the printer so that messages can be printed thereby; that is, contact 47 is open. Thirdly, the transmitter is connected into the circuit to permit the proper transmission of the message; that is, the contact 48 is closed thereby permitting rotation of the transmitter distributor shaft. It is evident, from the foregoing description of the send position of the break mechanism, that these three things have been achieved.

To place the break mechanism in the receive position it is necessary to depress lever 49 to the middle position; or that position shown in full lines in Fig. 6. This movement of lever 49 affects the associated lever mechanism in the following manner: Lever 49 being thus slightly rotated in a clockwise direction (as viewed in Fig. 3) releases arm 98 of lever 96 and simultaneously raises arm 72- of lever 50 causing it to rotate slightly in a clockwise direction sufiiciently to permit lever 96 to rotate in a like direction about pivot 97 under the influence of spring 102 until arm 95 engages the shallow portion of double notch 94. This rotation of lever 96 causes portion 101 thereof to actuate contacts 4'7 and 48, closing contact 47 and opening contact 48. Three conditions are requisite to place the printing apparatus in the receivefposition; that is, in a. proper position to receive an incoming message (see Fig. 5). The first requisite is that the line contact 46 remain closed so that the signals coming in over the line can actuate the selector magnet 33.. The second requirement is that contact 47 be closed to render the keyboard inoperative; that is, the closing of the contact 47 shunts the keyboard contacts 21 and thereby diverts the current which would otherwise traverse the keyboard circuit, thus rendering said circuit ineffectual upon the closure of contacts 21. The third requisite is that contact 48 be open to render the transmitting distributor inoperative by stopping rotation of its shaft, since it is obvious that it is not feasible to send a message while receiving one on the same apparatus. It is apparent, therefore, that the lever arrangement of the send-receive break mechanism just described effects these three conditions.

The purpose of the break position of the, sendreceive break mechanism and the reasons therefor will now be fully set forth. The further rotation of lever 49 in a clockwise direction (viewed in Fig. 6) about pivot '76 raises end 72 of lever 50 to impart further rotative motion in a like direction to lever 50 about its pivot 85. Arm 87 is likewise rotated and lateral portion 91 thereof is brought into operative engagement with extension arm of contact switch 46 and urges the arm to the right to open or break said contact.

The result of breaking the circuit including contact 46 is to deenergize the selector magnet 33 at the remote end of the line, which is normally energized while the printer is in use or is connected to the line circuit. As is well known, in order to initiate the selection of a character or function a start impulse must be transmitted, and since this impulse is of a spacing or no-current nature, the'selector magnet becomes deenergized and causes the rotation of cam barrel 40 (Fig. 4) of the selector mechanism to effect the selection of a character or function. Now, the deenergization of the selector magnet 33 by means of the herein described break mechanism is equivalent to its deenergization by means of a start impulse; that is, the effect is identical. So, when the lever 49 has been depressed to the lowest or break position, the cam barrel 40 of the printing unit at the remote end of the line will rotate, causing blank code combinations to be set up or selected. Therefore, when lever 49 is held down or depressed for a period equivalent to the transmission of two or more blank signals or selections the apparatus at the receiving end of the line will be aifected in the following manner:

For the purpose of illustration it will be assumed that the operator at one end of the line, who shall be referred to herein as the sender, is transmitting messages to the operator at the other or remote end of the line, who shall be referred to as the receiver. Under these circumstances lever 49 of the senders printing unit is in the send position and similarly lever 49 of the receivers printing unit is in the receive position. So, should the receiving operator desire to interrupt the sender for some reason, for instance to ask the sender to repeat his message, the receiving operator will simultaneously depress his levers 49 and 69 to the lowest or break position, holding the levers in that position for a short interval of time equivalent to the transmission of at least two signals. The result of this, as above noted, is to break the line circuit which is equivalent to transmitting no-current or spacing impulses, thereby initiating the operation of the senders selector mechanism. Blank signals or combinations are therefore set up,

I and the selector vanes 37 are so set as to effect the selection of the blank function lever 103, Fig. 7,, which is thereby permitted to rotate about common shaft '104 in a clockwise direction under the influence of its spring 105. Function lever 103 is provided with an outwardly extendingarm 106, adapted to cooperate with arm 107 of T-lever 108.

Referring to Fig. 7, T-lever 108 is pivotally con,- nected at 109 to the vane frame 111 (as indicated in Fig. 1), and comprises arms 107, 112 and 113 and is adapted to oscillate or rock slightly to the right and left; so, when it is rocked to the left about pivot 109it assumes the operated position and to the right, the unoperatedi position.

,It is held in either of these positions by means of a spring washer 114. To the end of the vertical arm 112 of T-lever 108 is pivotally connected arm 115 of substantially T-shaped lever 89, previously alluded to. Arm 116 of lever 89 is provided with laterally disposed portion 117 overlapping aforementioned portion 88 of lever 50 to cooperate therewith, said portion 117 having an adjusting screw 118 mounted thereon. The purpose of adjusting screw 118 is readily appreciated when it is recalled that the two main parts of the send-receive break mechanism are separable at this point and therefore are subject to misadjustment.

Pivotally connected at 123 to arm 115 of T-lever 89 and appropriately positioned thereon with respect to T-lever 108 and function lever arm 106 is intermediate lever 124. Lever arms 125 and 126 of lever 124 are provided at their ends with op-e positely disposed portions 127 and 128, respectively, adapted to lie in the plane of rotation of said lever 124. Lever arm 125 has projection 129 to which is attached one end of a spring 131, the other end of which is secured to projection 132 on arm 112 of T-lever 108. Spring 131, therefore, does not affect T-lever 108, but tends to rotate intermediate lever 124 in a clockwise direction about pivot 123, thereby holding arm 125 against limiting stop 133, adjustably mounted on vane frame 111. Intermediate lever 124 is so positioned with respect to T-lever 108 that the upper surface 134 of portion 128 is elevated slightly above arm 107 of T-lever 108 so as to prevent portion 128 from swinging underneath extension 106 until certain conditions have been fulfilled. Lever 125 remains in its normal position while T-lever 108 assumes its hereinbefore mentioned unoperated position. While in said normal position, lever 124 is so .disposed that portion 128 is held clear of arm 106 of function lever 103 by means of stop member 133, because of the fact that the clockwise movement of T-lever 108 tends to carry the intermediate lever 125 toward the right, which movement is resisted-by stop 133, thus causinglever 125 to rotate in a counterclockwise direction.

Universal function lever 135, Fig. 7, is also retatably mounted on common fulcrum 104 and is normally tending to rotate in a clockwise direction under the influence of its spring 136. Lever 135 is not provided with any code notches and thereby tends to function during every cycle of operation; however, this lever is provided with an outwardly extending arm 137 which is adapted to cooperate with arm 113 of T-lever 108. As will hereinafter appear, universal function lever 135 constantly attempts to restore T-lever 108 to its unoperated or clockwiseposition, but since its spring 136 is weaker than spring 105 individual to function lever 103 its influence upon T-lever 108 will not prevail while said T-lever 108 is under the influence of function lever 103.

The mechanical operation of the send-receive break mechanism will now be fully described. The manner of selecting function lever 103 was previously noted, as was also the fact that said lever 103 is provided with an extension arm 106 adapted to cooperate with arm 107 of T-lever 108. Arm 106 is also adapted to cooperate with. portion 128 of intermediate lever 124 when portion 128 swings into the downward path of said arm. During the cycle of operations inaugurated by the first blank code signal, the consequent rotation of the blank function lever 103 and the resulting downward movement of extension arm 106 will impart slight rotation in a counterclocke wise'direction to T-lever 108 about its pivot 109. T-lever 108 has now assumed its operated position and will hold this position due to the effect of spring washer 114. While thus rotating to its. operated position T-lever 108 through its vertical arm 112 imparts motion toward the left to T-lever 89 which carries with it intermediate lever 124 which is thus caused by the tension of spring 131 to rotate in a clockwise direction about its pivot 123, but since, as has been noted, portion 128 of lever 124 is so disposed as to be slightly higher than arm 107, it is apparent that the end of portion 128 will bear against the side of the exten- I sion arm 106.while said lever 103 remains operated.

Now, such is the condition that always obtains when one blank signal is received by the printer. In the normal transmission or reception of a message a blank signal is followed by a character or function signal, and the T-lever 108 is thereby restored to its normal clockwise or unoperated position by being subjected to the influence of universal function lever 135. But, as was hereinbefore noted, the operation of the printing 'unit could not be interrupted except by the reception of a succeeding blank signal. Upon the completion of the cycle initiated by the first blank signal, the blank function lever 103 is restored to its normal position by function bail 138, thereby raising extension ,arm 106 to its original, uppermost. position. T-lever 108 continues to assume its operative position due to the pressure of spring washer 114, and intermediate lever 124 is permitted to continue its rotation in a clockwise direction under the influence of spring 131 since the elevation of the end of the arm 106 due to the restoration of function lever 103 to its normal unselected position has caused the disengagement of portion 128, permitting it to swing into the downward path of arm 106.

The break mechanism is now properly positioned to receive the second blank signal, which when received causes the selection and reoperation of function lever 103. The consequent downward movement of arm 106 will now be intercepted by portion 128 of intermediate lever 124, and lever 124 will thereby be urged downward to impart in turn rotative motion in a counterclockwise direction to T-lever 89 about its pivotal connection to lever 108. T-lever 89 thus will impart through its overlapping portion 117 clockwise motion to lever to set the apparatus in the "receive position by closing contact 47, thereby shunting the keyboard contacts and opening contact 48, preventing the further rotation of the transmitting, distributor shaft. The senders printing apparatus is thereby automatically rendered inoperative insofar as his ability further to transmit messages is concerned; and noting the interruption, he awaits the message to be sent to him from the distant station. The sender becomes aware of the interruption when he discovers that the further operation of the keys of his apparatus has no effect.

The electrical circuit which forms a part of the present invention is shown in Fig. 5, the stations A and B each being combination sending and receiving stations. The circuits at A and B are alike, and the same parts, when foundnecessary to be referred to, are designated by the same reference numerals. Referring to station A, it will be noted that since the station which it represents is in the send position, contacts 46 and 48 are closed, and contact 47 is open. Also, since the station B is in the receive position, its contacts 46 and 47 are closed, and contact 48 is open. As is well known, messages can be transmitted from the "send" station either by means of a keyboard through its contacts 21,

previously mentioned; or by meansof a tape transmitter 139 through its contacts 141 and dis tributor 142.

If a tape transmitter is used, manually operated switch 6'7 is closed, as shown, but if the keyboard is used to transmit messages the tape trans mitter switch is left open, as shown in dotted position (station A). Assuming in the first in stance, that the tape transmitter is used, the closing of the tape stop switch 6'7 will effect the energization of stop magnet 65 by establishing a circuit from positive battery through contact 48 of the send-receive break mechanism, over wire 64, through magnet 65, through tape stop contact 66, through switch 67, over wire 68 to negative battery. Energized magnet 65 thereupon attracts its armature 143 and initiates the operation of the transmitter, in well known manner.

It will be next assumed that the keyboard is used to transmit messages from the sending station A instead of the tape transmitter. In this case the manually operated tape stop switch 6'7 is opened, thus rendering the tape transmitter inoperative. The circuit for transmitting code signal impulses over the line wire is now completed from grounded battery 51, over wire 52, through keyboard contact 53, over wires 54 and 55, through break contact or switch 46, through polar relay 58 (which controls selector magnet 33), over wire 59, through transmitting distributor 61 (as shown), over line wire 62, thence through a similar circuit at the receiving station B.

In the event that the receiving station B should desire to interrupt the sending station A contact 46 at the receiving station will be manually held open momentarily, thereby opening companion contact 4'7 and closing companion contact 48, it being noted that the contacts 47 and 48 are always affected simultaneously. Opening the contact 48 at station A thus breaks the circuit controlling the start magnet 65 which magnet then becomes deenergized, thereby releasing its armature 143 to prevent rotation of distributor 61. The closing of contact 4'7 shunts the keyboard contacts 21 and 53 thus directing the current from wire 54, through contact 47, over wire 63, then back to grounded battery 51, thereby rendering the keyboard inoperative. -It is thus seen that the opening of contact 46 of either station breaks the signal line circuit.

Although the present invention has been disclosed in connection with a combination transmitting and recording apparatus, it is, of course, understood that the invention is capable of embodiment in many forms other than that particularly disclosed without departure from the spirit and scope of the invention as defined in the appended claims.

.What is claimed is:

1. Ina printing telegraph system, a plurality of stations, a transmitting and a receiving mechanism at each station, and means associated with each station for interrupting effective transmission from a remote transmitting station and invariably and automatically conditioning the receiving mechanism at the said transmitting station for message reception purposes.

2. In a printing telegraph system, a plurality of stations interconnected by a single channel of communication, a transmitting and a receiving printing mechanism at each station, and means associated with the mechanism at each station when receiving to interrupt eifective transmission thereto from another station and to condition invariably and automatically the mechanism at said other transmitting station for reception.

. 3. In a printing telegraph system, a plurality of interconnected stations, a duplicate transmitting and receiving apparatus at each station con vertible from sending to receiving and vice versa,

and means associated with each apparatus when rece ving apparatus at each station, and means associated with each apparatus and responsive to successive code impulses of a predetermined character to convert automatically the other apparatus from sending to receiving.

5. In a printing telegraph system, a plurality of intercommunicating stations, transmitting and receiving apparatus at each station, means whereby a receiving station can interrupt the transmitting apparatus at a remote transmitting station and render said transmitting apparatus inoperative, and invariably and automatically condition the receiving apparatus at said transmitting station to receive a message.

6. In a telegraph system, a plurality of intercommunicating stations, a combination transmitter and recorder at each station, individual circuits therefor, a plurality of contacts identified with each of said individual circuits, and code controlled means in said recorders to actuate said contacts at the will of any other of said stations to condition said transmitters and recorders for receiving messages.

'7. In a combination sending and receiving telegraph apparatus, a selector mechanism, a plurality of elements selectively operated by said mechanism, a function lever selectively operated by said elements, switching meansv effective to condition the apparatus for sending or receiving purposes, and a system of T-levers operable by said function lever to operate said means to effect the change of the apparatus from a sending to a receiving instrument.

8. In a combination sending and receiving apparatus including a single magnet selector mechanism responsive to received code combinations of signaling impulses, means selectively operable by said selector mechanism upon the receipt of a predetermined code combination of impulses, and means effective upon two successive operations of said means to change the condition of said apparatus from sending, to receiving.

9. In a printing telegraph system, a plurality of stations, a combination sending and receiving apparatus at each station, each apparatus including a single magnet selector mechanism responsive to received code combinations of signaling impulses, a send-receive switch, and a solely mechanical interconnection between said mechanism and said switch to render said apparatus automatically changeable from the sending to the receiving position.

10. In a printing telegraph system, a plurality of stations, a combination sending and receiving apparatus at each station, each apparatus including a single magnet selector mechanism responsive to received code combinations of signaling impulses, a send-receive switch, a circuit breaker, a mechanical interconnection between said mechanism and said switch, and means effective upon actuation of said circuit breaker to effect through said mechanical interconnection the transposition of the apparatus from the send to the receive position.

11. In a printing telegraph system, a plurality of intercommunicating stations, a combination sending and receiving instrument at each station, each instrument including a selector mechanism responsive to received code combinations of signaling impulses transmitted from any one of said stations, a plurality of elements selectively operated by said mechanism, an interponent, switching means, a function lever selectively controlled by said elements, and means to render said function lever effective to establish through said interponent a change in said switching means,

12. In a combination sending and receiving telegraph instrument, a selector mechanism, a plurality of elements selectively operated by said mechanism, a first member periodically controlled by said elements, a second member invariably operated, a switching means, and a dually controlled element actuated by either said first or said second member, said second member adapted to render said dually operated member normally inoperative, and means whereby said first member when operated simultaneously with said second member s'upervenes said second member to determine the operability of said dually controlled element to effect a change in said switching means.

13. In a printing telegraph recorder, a selector mechanism, a plurality of elements selectively operated by said mechanism, a first member periodically controlled by said elements, a second member invariably operated, a switching means, an interponent, a dually controlled element actuated by either said first or said second members, and means whereby said first member when successively operated simultaneously with said second member is adapted to supervene said second member to operate through said interponent said dually controlled element to effect a change in said switching means.

14. In a printing telegraph system, a plurality of stations, a combination sending and receiving instrument at each station, each instrument including a plurality of selectable elements, a first member periodically controlled by said elements in response to a predetermined code signal, a sec ond member invariably operated, a switching means, a dually controlled element actuated by either said first or said second member, and means whereby any one of said stations controls selectively the first member at each of the other stations which when operated simultaneously with its associated second member is adapted to supervene said second member to determine the operability of said dually controlled element to establish a change in said switching means such that the apparatus at each of said other stations is converted from a sending to a receiving instrument.

15. In a combination sending and receiving telegraph instrument, a selector mechanism, a plurality of elements selectively operated by said mechanism, a first member periodically controlled by said elements, a second member invariably operated, a switching means, a reset lever therefor, an interponent carried by said reset lever, a dually controlled element actuated by either said first or said second members, and means whereby said first member when operated simultaneously with said second member is adapted to supervene said second member to operate said dually controlled element to condition said interponent such that the successive operation of said first member will efiect through said reset lever a change in said switching means. I

16. In a combination sending and receiving telegraph instrument, a selector mechanism, a plurality of elements selectively operated by said mechanism, a first member periodically controlled by said elements, a second member invariably operated, a switching means including an operating lever, a contact lever and a manually operable control lever therefor, an automatically operable reset lever for said switching means, an interponent carried by said reset lever, a dually controlled element actuated by either said first or said Second members, and means whereby said first member when operated simultaneously with said second member is adapted to supervene said second member to operate said dually controlled element to condition said interponent such that the successive operation of said first member will effect through said reset lever and said operating lever the operation of said contact lever to establish a change in said switching means and a corresponding change in said control lever.

17. In a combination sending and receiving telegraph instrument, a base portion comprising transmitting mechanism, a signal receiving portion detachably mounted on said base portion, send-receive switch mechanism appurtenant to said base portion and said signal receiving portion, and means to render said mechanism divisible whereby said signal receiving portion is adapted to be readily detachable from said base portion.

18. In a printing telegraph system, a plurality of stations, a combination sending and receiving apparatus at each station, each apparatus comprising a base portion including transmitting mechanism, a signal receiving portion detachably mounted on said base portion, send-receive switch mechanism appurtenant to both portions, a circuit breaker, and signal controlled means in said receiving portion effective upon actuation of said circuit breaker to effect through said switch mechanism the transposition of the apparatus from the send to the receive position.

19. In a printing telegraph system, a plurality of stations, a combination sending and receiving apparatus at each station, each apparatus comprising a base portion including transmitting mechanism, a signal receiving portion detachably mounted on said base portion, a send-receive switch mechanism appurtenant to both portions and divisible therebetween, a circuit breaker, said switch mechanism comprising in one part a transmitting-contact lever and in the other part a reset lever, and signal controlled means in said receiving portion effective upon actuation of said circuit breaker to effect through said levers the transposition of the apparatus from the send to the receive position.

20. In a communicating apparatus convertible from one condition to another, the combination of controlling mechanism adapted to be adjusted by electrical currents, a first element, a second element, and means operable by said controlling mechanism and adapted upon its successive operation to effect the consecutive operation of said elements to change the condition of the apparatus.

21. In a communicating apparatus convertible from a sending to a receiving condition and vice versa, the combination of controlling mechanism adapted to be adjusted by electrical currents, and means operable by said controlling mechanism and effectual upon its successive operation for changing the apparatus from a sending to a receiving condition.

22. In an apparatus convertible from one condition to another; the combination of controlling mechanism adapted to be adjusted by electrical currents, and means operable by said controlling mechanism to condition upon its first actuation the apparatus for conversion, and thereafter operable upon a consecutive actuation thereof to effectuate the conversion.

23. In a communicating apparatus, the combination of controlling mechanism adapted to be 5 adjusted by electrical currents, and a plurality receiving condition when the said one of said means is actuated a different number of times by the controlling mechanism.

24. In an apparatus convertible from one condition to another, the combination of controlling mechanism adapted to be adjusted by electrical currents, and a plurality of means operable by said controlling mechanism and so arranged that only one thereof at a time is actuated by said controlling mechanism, one of said means operable upon its first actuation to condition the apparatus for conversion, and thereafter operable upon a consecutive actuation thereof to effectuate the conversion.

25.. In a combination sending and receiving apparatus including a selector. mechanism responsive to received code combinations of signaling impulses, means selectively operable by said selector mechanism upon the receipt of a predetermined code combination of impulses, and means effective upon two successive operations of said means to change the condition of saidapparatus from sending to receiving.

26. In a combination sending and receiving apparatus including a selector mechanism responsive to received code combinations of signaling impulses, means selectively operable by said selector mechanism upon the receipt of a predetermined code combination of impulses, and means effective upon two consecutive operations of said means to change the condition of said apparatus from sending to receiving.

27. In a communicating system, a plurality of stations, transmitters and recorders at each station, a control device associated with each transmitter, and means in each recorder operable under the control of. said device-for rendering at each station the receiving apparatus effective and the transmitting apparatus ineffective.

28. In a communicating system, a plurality of stations, a combination transmitting and receiving apparatus at each station, means in said apparatus responsive to a combination of code impulses of the same character for rendering the receiving apparatus effective and the transmitting apparatus ineffective, and a control device associated with each apparatus effective when operated to control the actuation of said means.

29. In a communicating system, a plurality of stations, a combination transmitter and receiver at each station, means in each receiver responsive to a combination of code impulses of the same character for rendering said receiver effective and its associated transmitter ineffective, and an auxiliary transmitting device associated with each transmitter'effective at the will of the operator to control the actuation of said means.

30. In a printing telegraph system, a plurality of interconnected stations, a transmitting and a receiving apparatus at each station convertible from sending to receiving and vice versa, and means associated with each apparatus when receiving acting solely to convert automatically the other apparatus from sending to receiving.

31. In a communicating system, a plurality of stations, 2. transmitting and a receiving apparatus at each station, and means associated with each station effective independently of the then transmitting station to interrupt transmission and to condition automatically the apparatus at mitting station for invariably and automatically said transmitting station for reception. conditioning the receiving mechanism at the said 32. In a printing telegraph system, a plurality transmitting station for message reception purof stations, a transmitting and. a receiving mechposes.

nism at each station, and mechanically operated STERLING MORTON.

means associated with each station for interrupt- HOWARD L. KRUM. ing efiective transmission from a remote trans- EDWARD E. KLEINSCHMIDT.

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